[QUESTION] Chapter 14: `data_augmentation` for classification of flowers not actually used?

In cell 48 of the notebook, the variable `data_augmentation` is created:
```python
data_augmentation = tf.keras.Sequential([
tf.keras.layers.RandomFlip(mode="horizontal", seed=42),
tf.keras.layers.RandomRotation(factor=0.05, seed=42),
tf.keras.layers.RandomContrast(factor=0.2, seed=42)
])
```

However, it doesn't seem to be used when training/finetuning the model even though the text in the book mentions: "let's create a data augmentation model that we will embed in our final model". (page 519)

Probably, the `data_augmentation` model should be used before the Xception model is called?